Telephony testing system

ABSTRACT

An electronic relay matrix ( 22 ) is connectable between a plurality of customer telephone lines and a plurality of testers ( 2, 20   1   -20   3 ). The electronic relay matrix ( 22 ) includes a line matrix ( 80 ) having a plurality of relay assemblies ( 82   1   -82   50 ). Each relay assembly ( 82 ) in a relaxed state connects together the line-side ( 12 ) and the drop-side ( 8 ) of one of the customer telephone lines. Each relay assembly ( 82 ) is adjustable to enable one of the plurality of testers ( 2, 20   1   -20   3 ) to be connected to the drop-side ( 8 ) and/or the line-side ( 12 ) of a desired customer telephone line.

This application claims the benefit of provisional application Ser. No.60/059,394 filed Sep. 19, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an electronic relay matrix utilized toselectively connect together a telephone line tester and a customertelephone line.

2. Description of the Prior Art

Until recently, telephone companies (TCs) have enjoyed a monopoly inlocal exchange carrier markets. Accordingly, in the event of troublewith their telephone service, a customer would notify their TC of thetrouble and the TC would initiate an automated test of the telephone andequipment of the customer experiencing the trouble. More specifically,as shown in FIG. 1, a TC tester 2 provides test and control signals to aTC switch 4. The control signals cause the TC switch 4 to selectivelyconnect telephony equipment of a customer, e.g., 6 ₁, to the TC tester 2through a drop-side 8 ₁ of a telephone line, a main distribution frame(MDF) 10, a line-side 12 ₁ of the telephone line, and the TC switch 4.Similarly, a customer 6 ₂ can be connected to the TC tester 2 through adrop-side 8 ₂, the MDF 10, a line-side 12 ₂ and the TC switch 4.

The Telecommunications (TELCO) Act of 1996 requires TCs to leasecustomer telephone lines, and specifically the drop-sides 8 of customertelephone lines, to rival telephone companies (RTCs). Hence, the TELCOAct breaks up the monopoly enjoyed by the TCs in the local exchangecarrier market.

With reference to FIG. 2, to enable an RTC to service the telephonyequipment of the customer 6 ₂ , the line-side 12 ₂ servicing thetelephony equipment of the customer 6 ₂ is disconnected from the TCswitch 4 and connected to an RTC switch 16 through an intermediatedistribution frame (IDF) 18. Hence, the RTC switch 10 can service thetelephony equipment of the customer 6 ₂ that heretofore was serviced bythe TC switch 4.

In the embodiment shown in FIG. 2, the TC switch 4 and the RTC switch 16are connected to their respective customers 6 ₁ and 6 ₂ through the maindistribution frame 10. Since the TC switch 4 services; only TCcustomers, i.e., 6 ₁, the TC tester 2 is not available to test theline-side 12 ₂, the drop-side 8 ₂ and the telephony equipment of the RTCcustomers 6 ₂. To test the line-side 12 ₂, the drop-side 8 ₂ and thetelephony equipment of the RTC customer 6 ₂ , the RTC must provide anRTC tester 20 connected to the RTC switch 16.

If the RTC customer 6 ₂ reports a problem with their telephone service,the RTC initiates testing of the drop-side 8 ₂, the line-side 12 ₂ andthe telephony equipment of the RTC customer 6 ₂ with the RTC tester 20.If no problem is found, an assumption is made that the leased TCequipment, i.e., the drop-side 8 ₂, the line-side 12 ₂ or the MDF 10, iscausing the customer problem and the RTC notifies the TC. Since theline-side 12 ₂ of the RTC customer 6 ₂ no longer runs through the TCswitch 4, the TC tester 2 is not able to access the line-side 12 ₂ forautomated testing. Hence, a craftsperson must be dispatched to runmanual tests of the line-side 12 ₂, the drop-side 8 ₂ and the telephonyequipment of the RTC customer 6 ₂. If trouble is found, the fault mustbe located and repaired.

The inability of the TC to automatically test the line-side 12 ₂, thedrop-side 8 ₂ and the telephony equipment of the RTC customer 6 ₂represents a potential for increased time to repair customer problems,increased use of human resources and increased costs due to theincreased use of human resources. The potential for this increased costis of sufficient concern that utility regulations require RTCs to payTCs for false trouble reports and no-problem-found situations. However,the regulations also provide that TCs can only bill RTCs for falsetrouble reports or no-problem-found situations if the TC is capable ofsubmitting a test printout to verify the results. However, since the TCsare unable to use the TC tester 2, automated test printouts are notreadily available. The lack of automated test printouts impedes theability of the TCs to invoice RTCs for false trouble reports andno-problem-found situations. With poor trouble handling procedures, theTCs and the RTCs may experience profit losses and possibly even customerlosses.

It is therefore an object of the present invention to provide a point ofaccess for testing non-switched customer lines and special servicecircuits using existing test equipment. It is an object of the presentinvention to provide an apparatus that enables TCs and RTCs to testtelephone lines leased to RTCs utilizing a TC tester or an RTC tester.Still further objects of the present invention will become apparent tothose of ordinary skill in the art upon reading and understanding thefollowing detailed description.

SUMMARY OF THE INVENTION

Accordingly, we have invented a test system for testing a firstplurality of telephone lines and a second plurality of telephone lines.The test system includes an electronic relay matrix (ERM) connectablebetween the line-side and the drop-side of each telephone line of thefirst plurality of telephone lines and connectable between the line-sideand the drop-side of each telephone line of the second plurality oftelephone lines. A first tester is connected to the ERM via theline-side of each of the first plurality of telephone lines and via afirst test path. A second tester is connected to the ERM via theline-side of each of the second plurality of telephone lines and via asecond test path. In response to a control signal on one of the firsttest path and the second test path, the ERM connects to one of the firsttest path and the second test path at least one of the line-side and thedrop-side of a telephone line of one of the first plurality of telephonelines and the second plurality of telephone lines.

In the absence of the control signal, the ERM connects together theline-side and the drop-side of each telephone line of the firstplurality of telephone lines and connects together the line-side and thedrop-side of each telephone line of the second plurality of telephonelines.

A first switch can be connected between the first tester and theline-sides of the first plurality of telephone lines. The firstswitch-is configured to connect the first tester to the line-side of oneof the first plurality of telephone lines. A second switch can beconnected between the second tester and the line-sides of the secondplurality of telephone lines. The second switch is configured to connectthe second tester to the line-sides of one of the second plurality oftelephone lines.

A third switch can be connected between a third tester and the ERM. Thethird switch is connected to the ERM via line-sides of a third pluralityof telephone lines. The third switch is configured to connect the thirdtester to at least one of the line-sides of the third plurality oftelephone lines. An intermediate distribution frame can be connectedbetween the second switch and the ERM and between the third switch andthe ERM. The intermediate distribution frame can be utilized to connecteach line-side of the second plurality of telephone lines and eachline-side of the third plurality of telephone lines to the second testerand the third tester, respectively.

We have also invented an electronic relay matrix (ERM) which isconnectable to a plurality of testers and a plurality of telephonelines. Each tester is connectable to the ERM through a test path andthrough the line-side of at least one of the plurality of telephonelines. The ERM includes a line matrix having a plurality of relayassemblies. Each relay assembly is configured to connect together theline-side and the drop-side of one of the plurality of telephone linesand to receive an address signal. A relay mechanism is connected betweenthe line matrix and the test paths. A controller is configured to detecta control signal on one of the test paths and to cause the relaymechanism to connect the one test path to the plurality of relayassemblies. The controller causes an address signal to be generatedwhereby one of the relay assemblies adjusts and connects the one testpath to at least one of a line-side and a drop-side of the telephoneline connected to the one relay assembly.

The ERM can include a plurality of current detectors, a multi-frequencydecoder, a TR reverse switch, a DC detect circuit and an AC detectcircuit. Each current detector can be configured to detect the presenceof the control signal on one of the test paths and to provide thecontroller with an indication thereof. The multi-frequency decoder canbe configured to decode the control signal on the one of the test pathsand to provide to the controller the decoded control signal. The TRreverse switch can be configured to reverse a polarity of a tip-ringpair which comprise the one test path. The DC detect circuit can beconfigured to detect a DC signal on one of the plurality of telephonelines and to provide to the controller an indication thereof. The ACdetect circuit can be configured to detect an AC signal on one of theplurality of telephone lines and to provide the controller with anindication thereof.

Each test path can include a ring lead, a tip lead and a sleeve lead.The plurality of current detectors can include a first plurality ofcurrent detectors which are each configured to detect the control signalon one of the tip lead and the ring lead of one of the test paths and toprovide to the controller an indication thereof. The plurality ofcurrent detectors can also include a second plurality of currentdetectors each configured to detect the control signal on the sleevelead of one of the test paths and to provide to the controller anindication thereof.

The relay mechanism can include a first relay, a second relay and thirdrelay. The first relay can be configured to connect the multi-frequencydecoder to one of the test paths in response to one of the plurality ofcurrent detectors detecting the control signal on the one test path. Thesecond relay can be configured to connect the DC detect circuit and/orthe AC detect circuit to the plurality of relay assemblies in responseto the controller receiving the decoded control signal. The third relaycan be configured to connect the one test path to the plurality of relayassemblies in response to the DC detect circuit and/or the AC detectcircuit detecting an absence of a DC signal and/or an AC signal on thetelephone line connected to the at least one relay assembly.

An address decoder can be connected between the controller and the linematrix. The address decoder can be configured to receive from thecontroller a signal that causes the address decoder to supply theaddress signal to the one of the relay assemblies.

We have also invented a method of testing a plurality of telephonelines. The method includes detecting an absence of subscriber activityon one of a plurality of telephone lines having its line-sideconnectable to one tester. In response to detecting the absence ofsubscriber activity, a test path of the one tester or the test path ofanother tester is connected to the line-side and/or the drop-side of theone of the plurality of telephone lines.

Lastly, we have invented an apparatus for testing a telephone line. Theapparatus includes a decoder which is connected to a controller andwhich is connectable to a test path. The decoder is configured to decodea control signal on the test path and to provide the decoded controlsignal to the controller. A line matrix is connected to the controllerand is connectable to a plurality of telephone lines each having aline-side and a drop-side. A telephone line detector is connected to thecontroller and is connectable to the plurality of telephone lines. Arelay mechanism is connected to the controller, the line matrix, thetelephone line detector and the test path of the first tester. Inresponse to receiving the decoded control signal, the controller causesthe line matrix to select one of the plurality of telephone lines andcauses the relay mechanism to connect the telephone line detector to theselected one of the plurality of telephone lines. In response to thetelephone line detector detecting an absence of activity on the selectedone of the plurality of telephone lines, the controller causes the relaymechanism to connect the test path to at least one of the line-side andthe drop-side of the selective one of the plurality of telephone lines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a prior art connection of a telephonecompany (TC) tester to a TC switch which services plural customer lines;

FIG. 2 is a block diagram of a prior art TC tester connected to a TCswitch which services a TC customer through a main distribution frameand a rival telephone company (RTC) tester connected to an RTC switchwhich services an RTC customer through the main distribution frame;

FIG. 3 is a block diagram of a TC/RTC switching and testing networkconnected to a main distribution frame through an electronic relaymatrix in accordance with the present invention;

FIGS. 4a-4 b are block diagrams of internal circuitry of the electronicrelay matrix of FIG. 3 including a plurality of relay assemblies;

FIG. 5 is a block diagram of two of the relay assemblies of FIG. 4b; and

FIG. 6 is a block diagram of the network shown in FIG. 3 including aplurality of customers connected to each of the RTC switches and the TCswitch.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIG. 3, a telephone company (TC) tester 2 is connectedto a TC customer 6 ₁ through a TC switch 4, a line-side 12 ₁, of atelephone-line, an electronic relay matrix (ERM) 22, a main distributionframe (MDF) 10 and a drop-side 8 ₁ of the telephone line. Connectedbetween the TC tester 2 and the ERM 22 is a line 24 ₁ which.includes asleeve S1 and a tip-ring pair TR1. The sleeve S1 and the tip-ring pairTR1 are utilized to pass test and control signals between the TC tester2 and the ERM 22.

A first rival telephone company (RTC₁) tester 20 ₁ is connected to anRTC₁customer 6 ₂ through an RTC₁ switch 16 ₁ , an intermediatedistribution frame (IDF) 18, a line-side 12 ₂ of a telephone line, theERM 22, the MDF 10 and a drop-side 8 ₂ of the telephone line. The RTC₁tester 20 ₁ is also connected to the ERM 22 by a line 24 ₂ whichincludes a sleeve S2 and a tip-ring pair TR2. A second rival telephonecompany RTC₂ tester 20 ₂, shown in phantom in FIG. 3, can be connectedto an RTC₂ customer 6 ₃ through an RTC₂ switch 16 ₂ , the IDF 18, aline-side 12 ₃ of a telephone line, the ERM 22, the MDF 10 and adrop-side 8 ₃ of the telephone line. Similarly, a third rival telephonecompany RTC₃ tester 20 ₃, shown in phantom in FIG. 3, can be connectedto an RTC₃ customer 6 ₄ through an RTC₃ switch 16 ₃, the IDF 18, aline-side 12 ₄ of a telephone line, the ERM 22, the MDF 10 and thedrop-side 8 ₄ of the telephone line. The RTC₂ tester 20 ₂ and the RTC₃tester 20 ₃ are also connected to the ERM 22 by lines 24 ₃ and 24 ₄which include sleeves S3 and S4 and tip-ring pairs TR3 and TR4,respectively. The sleeves S2-S4 and the tip-ring pairs TR2-TR4 of lines24 ₂-24 ₄ are utilized to pass test and control signals between the ERM22 and the RTC testers 20 ₁-20 ₃, respectively.

The line-side 12 ₁ and the line 24 ₁ define a first test path and asecond test path, respectively, between the TC tester 2 and the ERM 22.The first test path is utilized to convey test signals between the TCtester 2 and the TC customer 6 ₁ via the line-side 12 ₁ and thedrop-side 8 ₁ of the telephone line of the TC customer 6 ₁ . The secondtest path is utilized to convey test and control signals between the TCtester 2 and the ERM 22. The control signals conveyed via the line 24 ₁cause the ERM 22 to selectively connect to the line 24 ₁ one of thedrop-sides 8 ₁-8 ₄ connected to the MDF 10 and/or one of the line-sides12 ₁-12 ₄ connected to the ERM 22. When the line 24 ₁is connected to oneof the line sides 12 ₁-12 ₄ and/or one of the drop-sides 8 ₁-8 ₄, the TCtester 2 can supply test signals thereto.

Similarly, the line-sides 12 ₂-12 ₄ and the lines 24 ₂-24 ₄ define firstand second test paths, respectively, between the RTC testers 20 ₁-20 ₃and the RTC customers 6 ₂-6 ₄. The first test path is utilized to conveytest signals between the RTC testers 20 ₁-20 ₃ and the RTC customers 6₂-6 ₄ via the line-sides 12 ₂-12 ₄ and the drop-sides 8 ₂-8 ₄,respectively. The second test paths are utilized to convey test andcontrol signals between each RTC tester 20 ₁-20 ₃ and the ERM 22. Thecontrol signals conveyed via one of the lines 24 ₂-24 ₄ cause the ERM 22to selectively connect to the one of the lines 24 ₂-24 ₄, one of thedrop-sides 8 ₁-8 ₄ connected to the MDF 10 and/or one of the line-sides12 ₁-12 ₄ connected to the ERM 22. When one of the lines 24 ₂-24 ₄ isconnected to the one of the line-sides 12 ₄-12 ₄ and/or the one of thedrop-sides 8 ₁-8 ₄, the RTC tester 20 ₁-20 ₃ connected to the one of thelines 24 ₂-24 ₄ can supply test signals thereto. When connected to aline-side and a drop-side, one of the lines 24 ₁-24 ₄ is preferablyconnected to the line-side and the drop-side of the telephone lineconnected to one customer. However, one of the lines 24 ₁-24 ₄ can becross-connected to the line-side of the telephone line connected to onecustomer and the drop-side of the telephone line connected to anothercustomer.

With reference to FIGS. 4a-4 b, and with ongoing reference to FIG. 3,the ERM 22 includes current detectors 40 ₁-40 ₄ connected to detectcurrent flowing in the tip leads or the ring leads of the tip-ring pairsTR1-TR4 of lines 24 ₁-24 ₄, respectively. A controller 50 is connectedto receive from each of the current detectors 40 ₁-40 ₄ an outputindicative of a current detected thereby. Sleeve currentdetect/terminations 44 ₁-44 ₄ are connected to detect current flowing inthe sleeves S1-S4 of lines 24 ₁-24 ₄, respectively. The controller 50 isconnected to receive from each of the sleeve current detect/terminations44 ₁-44 ₄ an output indicative of the-current detected thereby.

A relay 60, is connected between the tip-ring pair TR1 of line 24 ₁ anda multi-frequency (MF) decoder 62. The controller 50 is connected to anoutput of the MF decoder 62. A TR reverse switch 64 is connected betweenthe relay 60 and a control output of the controller 50. A relay 66 isconnected between the tip-ring pair TR1 and a tip-ring pair TRA. Thetip-ring pair TRA are connected to inputs of a DC detect circuit 68 andan AC detect circuit 70. The DC detect circuit 68 and the AC detectcircuit 70 have outputs connected to inputs of the controller 50. Arelay 72 is connected between tip-ring pairs TR2-TR4 of lines 24 ₂-24 ₄and an isolation relay 74. The isolation relay 74 is connected betweenthe relay 72 and a tip-ring pair TRB. The tip-ring pair TRB areconnected to inputs of a DC detect circuit 76 and an AC detect circuit78. The DC detect circuit 76 and the AC detect circuit 78 have outputsconnected to inputs of the controller 50. A node between the relay 72and the isolation relay 74 is connected to the relay 60. Each of therelays 60, 66, 72 and 74 have control inputs connected to relay controloutputs of the controller 50. The DC detect circuits 68 and 76 and theAC detect circuits 70 and 78 each include internal relays (not shown)which, under the control of the controller 50, can selectively connectthe DC detect circuits 68 and 76 and the AC detect circuits 70 and 78 tothe tip-ring pair TRA and the tip-ring pair TRB, respectively.

The ERM 22 includes a line matrix 80, shown in FIG. 4b, which has aplurality of relay assemblies 82 ₁-82 ₅₀. Each relay assembly 82 ₁-82 ₅₀includes a plurality of relays each having a plurality of contacts. Therelay assemblies 82 ₁-82 ₅₀ will be described in greater detailhereinafter.

An X-decoder 84 and a Y-decoder 86 each have one or more inputsconnected to receive address signals from the controller 50. The addresssignals received by the X-decoder include a drop-side enable signal, aline-side enable signal, a matrix enable signal and X-address signals.In response to receiving the address signals, the X-decoder 84 suppliesto the line matrix 80 an X-DEC signal. Similarly, the address signalsreceived by the Y-decoder 86 include the drop-side enable signal, theline-side enable signal, the matrix enable signal and Y-address signals.In response to receiving the address signals, the Y-decoder 86 suppliesto the line matrix 80 a Y-DEC signal. The X-DEC signal and the Y-DECsignal received at the line matrix 80 coact to select one of the relayassemblies 82 ₁-82 ₅₀ and to cause the selected one of the relayassemblies 82 ₁-82 ₅₀ to adjust and connect the line-side 12 and/or thedrop-side 8 of the telephone line connected thereto to a tip-ring pairTR Bus.

The tip-ring pair TR Bus are connected to inputs of each of the relayassemblies 82 ₁-82 ₅₀ of the line matrix 80. A relay 88 is connectedbetween the tip-ring pair TRA and the tip-ring pair TR Bus. The relay 88is also connected between the tip-ring pair TRB and the tip-ring pair TRBus. The relay 88 has a control input connected to a relay controloutput of the controller 50. In response to a signal at its controlinput, the relay 88 selectively connects the tip-ring pair TRA or thetip-ring pair TRB to the tip-ring pair TR Bus. The relays 60, 66, 72, 74and 88 form a relay mechanism which can selectively connect one of thetip-ring pairs TR1-TR4 of lines 24 ₁-24 ₄ to the relay assemblies 82₁-82 ₅₀ of the line matrix 80 via the tip-ring pair TR Bus.

In operation, contacts of the relay assemblies 82 ₁-82 ₅₀ are adjustedin response to the TC tester 2 or one of the RTC testers 20 ₁-20 ₃conveying a control signal on the tip lead of one of the tip-ring pairsTR1-TR4 of lines 24 ₁-24 ₄, respectively. In response to the controlsignal, the controller 50 causes the contacts of one of the relayassemblies 82 ₁-82 ₅₀ to adjust and connect the line-side 12 or thedrop-side 8 of the telephone line connected to the one of the relayassemblies 82 ₁-82 ₅₀ to the tip-ring pair of the line utilized toconvey the control signal. This connection enables the TC tester 2 orone of the RTC testers 20 ₁-20 ₃ to convey test signals to the line-side12 or the drop-side 8 of the telephone line connected to the one of therelay assemblies 82 ₁-82 ₅₀ through the tip-ring pair of the lineutilized to convey the control signal. Alternatively, in response to thecontrol signal, the controller 50 causes the contacts of one of therelay assemblies 82 ₁-82 ₅₀ to adjust and bridge connect the tip-ringpair of the line utilized to convey the control signal to the telephoneline connected to the one of the relay assemblies 82 ₁-82 ₅₀. Thisbridge connection enables the DC detect circuits 68 or 72 and/or the ACdetect circuits 70 or 78 to detect the presence or absence of activityon the telephone line connected to the one of the relay assemblies 82₁-82 ₅₀. In the absence of a control signal being conveyed on one of thetip-ring pairs TR1-TR4 of the lines 24 ₁-24 ₄, the contacts of eachrelay assembly 82 ₁-82 ₅, are in a relaxed, normally closed state whichforms a pass-through connection between the line-side 12 and thedrop-side 8 of the telephone line connected thereto.

More specifically, if the TC tester 2 is utilized to test a selectedtelephone, line, the TC tester 2 supplies to the ERM 22 a control signalon the tip lead of the tip-ring pair TR1 of the line 24 ₁. The controlsignal on the tip-ring pair TR1 of the line 24 ₁ is detected by thecurrent detector 40 ₁. In response to detecting the control signal, thecurrent detector 40, supplies to the controller 50 a signal indicativethereof. In response to the signal from the current detector 40 ₁, thecontroller 50 causes the relay 60 to adjust and connect the tip-ringpair TR1 of the line 24 ₁ to the MF decoder 6 ₂ and the TR reverseswitch 64. The controller 50 causes the TR reverse switch 64 to reversethe polarity of the tip-ring pair TR1 of the line 24 ₁. In response todetecting the reversed polarity of the tip-ring pair TR1 of the line 24₁, the TC tester 2 supplies control signals to the tip-ring pair TR1 ofthe line 24 ₁. The MF decoder 62 converts the control signals suppliedon the tip-ring pair TR1 of the line 24 ₁ into digital signals usable bythe controller 50. The digital signals from the MF decoder 62 areprocessed by the controller 50 into the address signals that areprovided to the X-decoder 84 and the Y-decoder 86. The address signalscause the X-decoder 84 and the Y-decoder 86 to supply to the line matrix80 the X-DEC signal and the Y-DEC signal. The digital signals from theMF decoder 62 also cause the controller 50 to adjust the relay 88 toconnect the tip-ring pair TRA to the tip-ring pair TR Bus and cause thecontroller 50 to connect the DC detect circuit 68 and the AC detectcircuit 70 to the tip-ring pair TRA.

The X-DEC signal and the Y-DEC signal received by the line matrix 80cause one of the relay assemblies 82 ₁-82 ₅₀ to adjust and connect thetip-ring pair TR Bus to (i) a line-side 12 and a drop-side 8 of theselected telephone line in a bridge mode, (ii) the line-side 12 of theselected telephone line or (iii) the drop-side 8 of the selectedtelephone line. When connected in the bridge mode, the tip-ring pair TRBus connects the line-side 12 and the drop-side 8 of the selectedtelephone line to the DC detect circuit 68 and the AC detect circuit 70via the tip-ring pair TRA. The DC detect circuit 68 and the AC detectcircuit 70 detect the presence or absence of a respective DC voltage oran AC voltage, indicative of activity on the selected telephone line,and provide to the controller 50 outputs indicative thereof. In theabsence of the DC detect circuit 68 or the AC detect circuit 70detecting the respective DC voltage or AC voltage on the selectedtelephone line, the controller 50 causes the DC detect circuit 68 andthe, AC detect circuit 70 to be isolated from the tip-ring pair TRA andcauses the TR reverse switch 64 to re-reverse the polarity of thetip-ring pair TR1.

In response to detecting the re-reversal of the polarity of the tip-ringpair TR1, the TC tester 2 adapts itself to convey control signals to theERM 22 on the sleeve S1 of the line 24 ₁. The control signals on thesleeve S1 are detected by the sleeve current detect/termination 44 ₁which supplies to the controller 50 signals indicative thereof. Inresponse to the signals from the sleeve current detect/termination 44 ₁,the controller 50 causes the relay 66 to adjust and connect the tip-ringpair TR1 of the line 24 ₁ to the tip-ring pair TRA. Connecting thetip-ring pair TR1 of line 24 ₁ to the tip-ring pair TRA creates betweenthe TC tester 2 and the selected telephone line a test path whichincludes the tip-ring pair TR1 of line 24 ₁, the tip-ring pair TRA andthe tip-ring pair TR Bus.

Similarly, a control signal supplied to the ERM 22 by one of the RTCtesters 20 ₁-20 ₃ on the tip lead of one of tip-ring pairs TR2-TR4 oflines 24 ₂-24 ₄ is detected by one of the current detectors 40 ₂-40 ₄,respectively. In response to detecting the control signal, the one ofthe current detectors 40 ₂-40 ₄ supplies to the controller 50 a signalindicative thereof. In response to the signal from the one of thecurrent detectors 40 ₂-40 ₄, the controller 50 causes the relays 60 and72 to adjust and connect the one of the tip-ring pairs TR2-TR4 of thelines 24 ₂-24 ₄ to the MF decoder 6 ₂ and the TR reverse switch 64. Thecontroller 50 causes the TR reverse switch 64 to reverse the polarity ofthe one of the tip-ring pairs TR2-TR4 of the lines 24 ₂-24 ₄.

In response to detecting the reversed polarity, the one of the RTCtesters 20 ₁-20 ₃ supplies control signals on the one of the tip-ringpairs TR2-TR4 of the lines 24 ₂-24 ₄. The MF decoder 62 converts thecontrol signals into digital signals usable by the controller 50. Thedigital signals from the MF decoder 62 are processed by the controller50 into the address signals that are provided to the X-decoder 84 andthe Y-decoder 86. The address signals cause the X-decoder 84 and theY-decoder 86 to supply to the line matrix 80 the X-DEC signal and theY-DEC signal. The digital signals from the MF decoder 62 also cause thecontroller 50 to adjust the relay 88 to connect the tip-ring pair TRB tothe tip-ring pair TR Bus and cause the controller 50 to connect the DCdetect circuit 76 and the AC detect circuit 78 to the tip-ring pair TRB.

The X-DEC signal and the Y-DEC signal received by the line matrix 80cause one of the relay assemblies 80 ₁-80 ₅₀ to adjust and connect thetip-ring pair TR Bus to (i) a line-side 12 and a drop-side 8 of aselected telephone line in a bridge mode, (ii) the line-side 12 of theselected telephone line or (iii) the drop-side 8 of the selectedtelephone line. When connected in the bridge mode, the tip-ring pair TRBus connects the line-side 12 and drop-side 8 of the selected customertelephone line to the DC detect circuit 76 and the AC detect circuit 78via the tip-ring pair TRB. The DC detect circuit 76 and the AC detectcircuit 78 detect the presence or absence of a respective DC voltage oran AC voltage, indicative of activity on the selected customer telephoneline, and provide to the controller 50 outputs indicative thereof. Inthe absence of the DC detect circuit 76 or the AC detect circuit 78detecting the respective DC voltage or AC voltage on the selectedcustomer telephone line, the controller 50 causes the DC detect circuit76 and the AC detect circuit 78 to be isolated from the tip-ring pairTRB and causes the TR reverse switch to re-reverse the polarity of theone of the tip-ring pairs TR2-TR4 of the lines 24 ₂-24 ₄.

In response to detecting the re-reversal of the polarity, the one of theRTC testers 20 ₁-20 ₃ adapts itself to convey control signals to the ERM22 on one of the sleeves S2-S4 of the lines 24 ₂-24 ₄ corresponding tothe one of the tip-ring pairs TR2-TR4 of lines 24 ₂-24 ₄. The controlsignals on the one of the sleeves S2-S4 of the lines 24 ₂-24 ₄ aredetected by one of the sleeve current detect/terminations 44 ₂-44 ₄which supplies to the controller 50 signals indicative thereof. Inresponse to the signals from the one of the sleeve currentdetect/terminations 44 ₂-44 ₄, the controller 50 causes the relays 72and 74 to adjust and connect the one of the tip-ring pairs TR2-TR4 ofthe lines 24 ₂-24 ₄ to the tip-ring pair TRB, thereby creating betweenthe one of the RTC testers 20 ₁-20 ₃and the selected telephone line, atest path which includes the one of the tip-ring pairs TR2-TR4 of thelines 24 ₂-24 ₄, the tip-ring TRB and the tip-ring TR Bus.

Referring to FIG. 5, and with ongoing reference to FIGS. 3 and 4a-4 b, apair of relay assemblies 82 ₁ and 82 ₂ are shown isolated from the linematrix 80. The relay assembly 82 ₁ includes a first double-poledouble-throw relay 90 ₁ and a second double-pole double-throw relay 92₁. The control inputs of the relays 90 ₁ and 92 ₁ are energizable viathe X-DEC signal and the Y-DEC signal supplied from the X-decoder 84 andthe Y-decoder 86, respectively. In a relaxed state, when the X-DECsignal and Y-DEC signal are not supplied to the control inputs of therelays 90 ₁ and 92 ₁, the drop-side 8 ₁ of the telephone line of the TCcustomer 6 ₁ is connected to the TC switch 4 through the normally closedcontacts of the relay 92 ₁ and the line-side 12 ₁ of the telephone lineof the TC customer 6 ₁.

To detect the presence or absence of customer activity on the telephoneline of the customer 6 ₁, the control inputs of the relay 90 ₁ areenergized by the X-DEC signal and the Y-DEC signal so that the contactsof the relay 90 ₁ are adjusted from the normally closed state to thenormally open state. This adjustment connects the tip-ring pair TR Busto the telephone line of the TC customer 6 ₁ in a bridge mode. When thetelephone line of the TC customer 6 ₁ is connected to the tip-ring pairTR Bus in a bridge mode and the relay 88 is adjusted so that thetip-ring pair TRA are connected to the tip-ring pair TR Bus, thecontroller 50 causes the DC detect circuit 68 and AC detect circuit 70to be connected to the tip-ring pair TRA to detect activity on thetelephone line of the TC customer 6 ₁.

If activity is detected on the telephone line of the TC customer 6 ₁ ,the DC detect circuit 68 and/or the AC detect circuit 70 supply to thecontroller 50 a signal indicative thereof. In response to the signalindicative of customer activity on the telephone line of the TC customer6 ₁, the controller 50 causes the relay 92 ₁ to maintain the connectionbetween the line-side 12 ₁ and the drop-side 8 ₁ of the telephone lineof the TC customer 6 ₁. For simplicity of illustration, the line-side 12and the drop-side 8 of each customer telephone line are illustrated as asingle line. However, each customer telephone line includes a tip-ringpair, e.g., TR₁ , which are connectable to the tip-ring pair TR Bus viathe line matrix 80.

If, however, no activity is detected on the telephone line of the TCcustomer 6 ₁, the DC detect circuit 68 and the AC detect circuit 70 donot supply signals to the controller 50. In the absence of receivingsignals from the DC detect circuit 68 and the AC detect circuit 70, thecontroller 50 causes the X-decoder 84 and the Y-decoder 86 to supply theX-DEC signal and Y-DEC signal to the control inputs of relays 90 ₁ and92 ₁. These signals cause the contacts of relays 90 ₁ and 92 ₁ to changestate to connect the tip-ring pair TR Bus to the drop-side 8 ₁ of thetelephone line of the TC customer 6 ₁ or the line-side 12 ₁ of thetelephone line of the TC customer 6 ₁.

To connect the drop-side 8, of the telephone line of the TC customer 6 ₁to the tip-ring pair TR Bus, the controller 50 causes the X-decoder 84and the Y-decoder 86 to supply to the relays 90 ₁ and 92 ₁ the X-DECsignal and the Y-DEC signal which cause the contacts of the relay 92 ₁to adjust to the normally open state and the contacts of relay 90 ₁ toadjust to, or remain in, the normally closed state. When the contacts ofrelays 90 ₁ and 92 ₁ are adjusted to these states, the tip-ring pair TRBus is connected to the drop-side 8 ₁ of the telephone line of the TCcustomer 6 ₁.

To connect the line-side 12 ₁ of the telephone line of the TC customer 6₁ to the tip-ring pair TR Bus, the controller 50 causes the X-decoder 84and the Y-decoder 86 to supply to the relays 90 ₁ and 92 ₁ the X-DECsignal and the Y-DEC signal which cause the contacts of relays 90 ₁ and92 ₁ to adjust to the normally open state. When the contacts of relays90 ₁ and 92 ₁ are adjusted to the normally-open state, the tip-ring pairTR Bus is connected to the line-side 12 ₁ of the telephone line of theTC customer 6 ₁.

The relay assembly 82 ₂, shown in FIG. 5, operates in the same manner asthe relay 82 ₁ described above. Specifically, the contacts of relays 90₁ and 92 ₂ of the relay assembly 82 ₂ are adjusted in response to theX-DEC signal and the Y-DEC signal supplied to the control inputs of therelays 90 ₂ and 92 ₂ to connect the tip-ring pair TR Bus to thedrop-side 8 ₂ and/or the line-side 12 ₂ of the telephone line of theRTC₁ customer 62 ₂.

The relay assemblies 82 ₁ and 82 ₂ are representative of the relayassemblies 82 ₃-82 ₅₀ shown in block diagram form in FIG. 4b. In theembodiment shown in FIG. 5, the telephone line of the TC customer 6 ₁ isconnected. to the TC tester 2 via the TC switch 4 and the relay assembly82 ₁. Moreover, the telephone line of the RTC₁ customer 6 ₂ is connectedto the RTC₁ tester 20 ₁, via the RTC₁ switch 16 ₁, the IDF 18 and therelay assembly 82 ₂. The TC customer 6 ₁, however, can be connected toone of the RTC switches 16 ₁-16 ₃ by disconnecting the line-side 12 ₁ ofthe TC customer 6 ₁ from the TC switch 4 and connecting the line-side 12₁ to a port of the IDF 18 which is connected to the one of the RTCswitches 16 ₁-16 ₃. Similarly, the RTC₁ customer 6 ₂ can be connected tothe TC switch 4, the RTC₂ switch 16 ₂ or the RTC₃ switch 16 ₃, bydisconnecting the line-side 12 ₂ from the port of the IDF 18 whichconnects the RTC₁ customer 6 ₂ to the RTC₁ switch 16 ₁ , and connectingthe line-side 12 ₂ to the TC switch 4 or a port of the IDF 18 which isconnected to the RTC₂ switch 16 ₂ or the RTC₃ switch 16 ₃. Othercustomer telephone lines can be connected to the TC switch 4 or one ofthe RTC switches 16 ₁-16 ₃ in a similar manner.

In the embodiment shown in FIG. 3, each of the TC switch 4 and the RTCswitches 16 ₁-16 ₃ are shown servicing one customer 6 ₁ and 6 ₂-6 ₄,respectively, via the MDF 10 and the ERM 22. However, as shown in FIG.6, a plurality of TC customers 100 can be connected to the TC switch 4via the line-sides 102 and the drop-sides 104 of a plurality oftelephone lines of the TC customers 100. Similarly, a plurality of RTC₁customers 110 can be connected to the RTC₁ switch 16 ₁ via theline-sides 112 and the drop-sides 114 of a plurality of telephone linesof the RTC₁ customers 110. Moreover, a plurality of RTC₂ customers 120can be connected to the RTC₂ switch 16 ₂ via the line-sides 12 ₂ and thedrop-sides 124 of a plurality of telephone lines of the RTC₂ customers,and a plurality of RTC₃ customers 130 can be connected to the RTC₃switch 16 ₃ via the line-sides 132 and the drop-sides 134 of a pluralityof telephone lines of the RTC₃ customers.

The TC switch 4 enables each of the line-sides 102 connected thereto tobe selectively connected to the TC tester 2. For example, in response toa control signal from the TC tester 2, the TC switch 4 connects the TCtester 2 to a selected one of the line-sides 102, e.g., line-side 12 ₁.Each RTC switch 16 ₁-16 ₃ enables each of the line-sides 112, 122 and132 connected thereto to be selectively connected to one of the RTCtesters 20 ₁-20 ₃. For example, in response to a control signal from theRTC tester 20 ₁, the RTC₁ switch 16 ₁ connects the RTC₁ tester to aselected one of the line-sides 112 ₁ e.g., line-side 12 ₂.

When testing is complete, the one of the TC tester 2 and the RTC testers20 ₁-20 ₃ conducting a test supplies to the ERM 22 via the correspondingsleeve S1-S4 of the lines 24 ₁-24 ₄ a test termination control signal.The sleeve current detect/termination 44 ₁-44 ₄ connected to the sleeveS1-S4 of the lines 24 ₁-24 ₄ on which the test termination controlsignal is supplied converts this signal into a digital test terminationcontrol signal which is supplied to the controller 50. In response toreceiving the digital test termination control signal, the controller 50causes the X-decoder 84 and the Y-decoder 86 to withhold from the linematrix 80 the X-DEC signal and the Y-DEC signal. In the absence of theX-DEC signal and the Y-DEC signal, the relay assemblies 82 ₁-82 ₅₀ ofthe line matrix 80 adjust to their normally closed state therebyconnecting together the line-side and the drop-side of each customertelephone line connected to the line matrix 80. The digital testtermination control signal also causes the controller 50 to adjust therelays 66 and 74, as necessary, to isolate the tip-ring pair TRA fromthe tip-ring pair TR1 of line 24 ₁ or to isolate the tip-ring pair TRBfrom one of the tip-ring pairs TR2-TR4 of lines 24 ₂-24 ₄, respectively.

Based on the foregoing, it can be seen that the ERM 22 enables the TCtester 2 or the RTC testers 20 ₁-20 ₃ to test the drop-side 8 and/or theline-side 12 of any telephone line connected to the respective MDF 10and/or the ERM 22. For security purposes, the controller 50 can beprogrammed to provide controlled access to telephone lines connected tothe MDF 10 and/or the ERM 22. For example, the controller 50 can beprogrammed so that the RTC testers 20 ₁-20 ₃ access only the telephonelines of their respective customers. Moreover, the controller 50 can beprogrammed to restrict access to telephone lines connected to the TCswitch 4 or one of the RTC switches 16 ₁-16 ₃.

The ERM 22 can include a plurality of line matrices 80 connected to thetip-ring pair TR Bus and the output of the X-decoder 84 and theY-decoder 86. The decoding capability of the controller 50, theX-decoder 84 and the Y-decoder 86 determine how many relay assemblies 82the ERM 22 includes. In a preferred embodiment, the ERM 22 includes fourline matrices 80, having fifty relay assemblies each, in a commonhousing that is connected to the MDF 10.

In the absence of being routed through a line matrix 80, the line-sideand drop-side of a customer telephone line are connected together. Whena line matrix 80 is installed, however, the line-side and/or drop-sideof the customer telephone line are connected to a relay assembly 82 inthe manner described above.

The invention has been described with reference to the preferredembodiment. Obvious modifications and alterations will occur to othersupon reading and understanding the preceding detailed description. It isintended that the invention be construed as including all suchmodifications and alterations insofar as they come within the scope ofthe appended claims or the equivalents thereof.

We claim:
 1. A test system for testing a first plurality of telephonelines and a second plurality of telephone lines, with each telephoneline having a line-side and a drop-side, the test system comprising: anelectronic relay matrix (ERM) connectable between the line-side and thedrop-side of each telephone line of the first plurality of telephonelines and connectable between the line-side and the drop-side of eachtelephone line of the second plurality of telephone lines; a firsttester connectable to the ERM via the line-side of each of the firstplurality of telephone lines and via a first test path; and a secondtester connected to the ERM via the line-side of each of the secondplurality of telephone lines and via a second test path wherein, inresponse to a control signal on one of the first test path and thesecond test path, the ERM connects to the one of the first test path andthe second test path at least one of the line-side and the drop-side ofa telephone line of one of the first plurality of telephone lines andthe second plurality of telephone lines.
 2. The test system as set forthin claim 1, wherein: in response to the control signal on the first testpath, the ERM connects to the first test path at least one of theline-side and the drop-side of one of the telephone lines of the firstplurality of telephone lines; and in response to the control signal onthe second test path, the ERM connects to the second test path at leastone of the line-side and the drop-side of one of the telephone lines ofthe second plurality of telephone lines.
 3. The test system as set forthin claim 1, wherein in the absence of the control signal, the ERMconnects together the line-side and the drop-side of each telephone lineof the first plurality of telephone lines and connects together theline-side and the drop-side of each telephone line of the secondplurality of telephone lines.
 4. The test system as set forth in claim1, wherein: in response to the control signal on the first test path,the ERM connects to the first test path at least one of the line-sideand the drop-side of one of the telephone lines of the second pluralityof telephone lines; and in response to the control signal on the secondtest path, the ERM connects to the second test path at least one of theline-side and the drop-side of one of the telephone lines of the firstplurality of telephone lines.
 5. The test system as set forth in claim1, further including at least one of: a first switch connected betweenthe first tester and the line-sides of the first plurality of telephonelines, with the first switch configured to connect to the first testerthe line-side of one of the first plurality of telephone lines; and asecond switch connected between the second tester and the line-sides ofthe second plurality of telephone lines, with the second switchconfigured to connect to the second tester the line-side of one of thesecond plurality of telephone lines.
 6. The test system as set forth inclaim 5, further including: a third tester; a third switch connectedbetween the third tester and the ERM, with the third switch connected tothe ERM via line-sides of a third plurality of telephone lines, and withthe third switch configured to connect to the third tester at least oneof the line-sides of the third plurality of telephone lines; and anintermediate distribution frame connected between the second switch andthe ERM and between the third switch and the ERM, with the intermediatedistribution frame configured to connect each line-side of the secondplurality of telephone lines and each line-side of the third pluralityof telephone lines to the second tester and the third tester,respectively.
 7. The test system as set forth in claim 1, furtherincluding a main distribution frame connected between the ERM and thedrop-sides of the first plurality of telephone lines and between the ERMand the drop-sides of the second plurality of telephone lines.
 8. Thetest system as set forth in claim 1, wherein the ERM includes: linematrix having a plurality of relay assemblies, with each relay assemblyconfigured to connect together the line-side and the drop-side of atelephone line of one of the first plurality of telephone lines and thesecond plurality of telephone lines, and with each relay assembly havinga control input configured to receive an address signal; a relaymechanism connected between the line matrix and the first test path andbetween the line matrix and second test path; and a controllerconfigured to detect a control signal on one of the first test path andthe second test path, with the controller, in response to detecting thecontrol signal, causing the relay mechanism to connect the one of thefirst test path and the second test path to the plurality of relayassemblies and causing an address signal to be generated to one of therelay assemblies whereby the one relay assembly adjusts and connects theone of the first test path and the second test path to at least one ofthe line-side and the drop-side of the telephone line connected to theone relay assembly.
 9. An electronic relay matrix (ERM) connectablebetween a plurality of testers and a plurality of telephone lines, witheach telephone line having a line-side and a drop-side, with each testerconnectable to the ERM through a test path and through the line-side ofat least one of the plurality of telephone lines, the ERM comprising: aline matrix including a plurality of relay assemblies, with each relayassembly configured to connect together the line-side and the drop-sideof one of the plurality of telephone lines, with each relay assemblyconfigured to receive an address signal; a relay mechanism connectedbetween the line matrix and the test paths of the plurality of testers;and a controller configured to detect a control signal on one of thetest paths, with the controller, in response to detecting the controlsignal, causing the relay mechanism to connect the one test path to theplurality of relay assemblies and causing an address signal to begenerated whereby one of the relay assemblies adjusts and connects theone test path to at least one of the line-side and the drop-side of thetelephone line connected to the one relay assembly.
 10. The ERM as setforth in claim 9, further including: a plurality of current detectors,with each current detector configured to detect the presence of thecontrol signal on one of the test paths and to provide to the controlleran indication thereof; a multi-frequency (MF) decoder configured todecode a control signal on the one of the test paths and to provide tothe controller the decoded control signal; a TR reverse switchconfigured to receive a control signal from the controller and, inresponse to receiving the control signal, reverse a polarity of atip-ring pair which comprise the one of the test paths; a DC detectcircuit configured to detect a DC signal on one of the plurality oftelephone lines and to provide the controller with an indicationthereof; and an AC detect circuit configured to detect an AC signal onone of the plurality.of telephone lines and to provide the controllerwith an indication thereof.
 11. The ERM as set forth in claim 10,wherein: each test path includes a ring lead, a tip lead and a sleevelead; and the plurality of current detectors include: a first pluralityof current detectors, each of which are configured to detect the controlsignal on one of the tip lead and the ring lead of one of the test pathsand to provide to the controller an indication thereof; and a secondplurality of current detectors, each of which are configured to detectanother control signal on the sleeve lead of one of the test paths andto provide to the controller an indication thereof.
 12. The ERM as setforth in claim 10, wherein the relay mechanism includes: a first relayconnected between the MF decoder and the test paths, with the firstrelay configured to connect the MF decoder to the one test path inresponse to one of the plurality of current detectors detecting thecontrol signal on the one test path; a second relay connected betweenthe plurality of relay assemblies and at least one of the DC detectcircuit and the AC detect circuit, with the second relay configured toconnect the at least one of the DC detect circuit and the AC detectcircuit to the plurality of relay assemblies in response to thecontroller receiving the decoded control signal; and a third relayconnected between the test paths and the plurality of relay assemblies,with the third relay configured to connect the one test path to theplurality of relay assemblies in response to the at least one of the DCdetect circuit and the AC detect circuit detecting an absence of a DCsignal and an AC signal, respectively, on the telephone line connectedto the at least one relay assembly.
 13. The ERM as set forth in claim 9,further including an address decoder connected between the controllerand the line matrix, with the address decoder configured to receive fromthe controller a signal that causes the address decoder to supply to theone relay assembly the address signal.
 14. An apparatus for testing atelephone line, the apparatus comprising: a controller; a decoderconnected to the controller and connectable to a test path, with thedecoder configured to decode a control signal on the test path and toprovide the decoded control signal to the controller; a line matrixconnected to the controller and connectable to a plurality of telephonelines, with each of the plurality of telephone lines having a line-sideand a drop-side; a telephone line detector connected to the controllerand connectable to the plurality of the telephone lines; and a relaymechanism connected to the controller, the line matrix, the telephoneline detector and the test path of the first tester, wherein: inresponse to receiving the decoded control signal, the controller causesthe line matrix to select one of the plurality of telephone lines andcauses the relay mechanism to connect the telephone line detector to theselected one of the plurality of telephone lines; and in response to thetelephone line detector detecting an absence of activity on the selectedone of the plurality of telephone lines, the controller causes the relaymechanism to connect the test path to at least one of the line-side andthe drop-side of the selected one of the plurality of telephone lines.15. The apparatus as set forth in claim 14, wherein the telephone linedetector detects at least one of an AC signal and a DC signal on theselected one of the plurality of telephone lines.